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Contains fulltext : 195443.pdf (publisher's version ) (Open Access)

Radboud University, 19 februari 2018, Promotor : Brock, R.E. Co-promotores : Kuppevelt, A.H.M.S.M. van, Daamen, W.F., Contains fulltext : 182800.pdf (publisher's version ) (Open Access), Based on the observation that skin heals without a scar during embryonic development, we investigated the possibilities of using principles found in embryonic development to design novel constructs. Such constructs may induce embryonic-like processes, potentially, and result in scarless healing when used for the treatment of full-thickness skin wounds. A comparison between two time points during embryonic development (E14 and E16), and one postnatal time point (P1) against adult skin (P90), resulted in a list of 20 growth factors. Two growth factors were selected and were successfully incorporated into a type I collagen-heparin scaffold. In addition, we created type I collagen scaffolds containing hyaluronic acid, since hyaluronic acid is suggested to be important during embryonic wound healing. During embryonic development gradients of effector molecules are important. In the thesis we present briefly the development of a scaffold containing a gradient of heparin. Overall we have set the first steps in the construction of embryonic scaffolds for tissue engineering, focusing on glycosaminoglycans, effector molecules and collagen.

Scheikunde is een abstract vak en vraagt veel inbeeldingsvermogen van de leerlingen. Applets zijn computerprogrammaatjes die daarbij van grote hulp kunnen zijn, omdat deze beter kunnen visualiseren en simuleren dan een plaatje kan. Met dit onderzoek is gepeild in welke mate applets gebruikt worden en waarop docenten letten bij de selectie van applets. Verder is nagegaan of er behoefte was aan een keurmerk. In dit onderzoek is gebruik gemaakt van een enquête die gehouden is bij 60 scholen in de provincie Gelderland en Utrecht. Uit de enquête is naar voren gekomen dat 44% van de docenten in de steekproef applets gebruikt. Verder zijn er 8 selectiecriteria uit het onderzoek gekomen die door scheikunde docenten worden gebruikt bij het selecteren van hun applets. Deze selectiecriteria zijn in te delen in drie categorieën, namelijk motivatie, presentatie en probleem oplossend vermogen. Dit onderzoek is interessant voor scheikunde docenten die overwegen applets te gaan gebruiken of geïnteresseerd zijn in het werken met applets.

01 november 2010, Contains fulltext : 88354.pdf (publisher's version ) (Closed access), The in vivo performance of tissue-engineered constructs is often based on generally accepted read-out parameters, like (immuno)histology. In this study, high-density gene expression microarrays and gene ontology (GO) analysis were used as a read-out tool to identify the biological processes occurring after implantation of an acellular collagen-based skin construct using a rat full-thickness wound model. A freely-available program (DAVID) was used to identify up/downregulated biological processes (GO-terms) and results were compared to wound healing/regeneration without a construct. The entire process from RNA isolation to biological interpretation is explained step-by-step. Conventional (immuno)histology was used to validate the biological processes identified and indicate that microarray analysis may provide a valuable, fast and unbiased tool to evaluate the in vivo performance of tissue-engineered constructs. However, challenges remain e.g. with regards to the development of specific GO-terms and annotation of the (rat) genome.

Item does not contain fulltext, Group II nucleopolyhedroviruses (NPVs), e.g. Helicoverpa armigera (Hear) NPV and Spodoptera exigua (Se) MNPV (multiple NPV), lack a GP64-like protein that is present in group I NPVs, e.g. Autographa californica (Ac)MNPV, but have an unrelated envelope fusion protein named F. Three AcMNPV viruses were constructed by introducing AcMNPV gp64, HearNPV f or SeMNPV f genes, respectively, into a gp64-negative AcMNPV bacmid. Sf21 cells were incubated with different amounts of inactivated budded virus to occupy receptors and were subsequently infected with a fixed amount of infectious virus to compete for attachment. The results suggest that GP64 and F act on their own and use different receptors, while the two different F proteins exploit the same receptor. Additionally, gp64-null AcMNPV pseudotyped with baculovirus F was, in contrast to GP64, unable to transduce mammalian cells, indicating that mammalian cells do not possess baculovirus F protein receptors despite the structural similarity of baculovirus F to vertebrate viral fusion proteins.

Contains fulltext : 50063.pdf (publisher's version ) (Closed access)